In ongoing attempts to provide more efficient and convenient service to customers, many retailers have begun to use "point of sale check printers" to reduce the time required for a customer to manually fill out and sign a check. Most people have encountered delays at checkout lines when another customer waits until all of his or her items are checked or scanned to begin to fill out a check for the total purchase. Faster service is provided if the retailer uses a point of sale check printer. A point of sale check printer automatically enters information such as the date, amount of purchase and the name of the retail establishment in the proper spaces on a check, leaving only the signature line blank for the customer to sign. The process of paying by check is therefore made similar to a purchase by credit card, in which the date, the amount of the sale and the name of the retail establishment are provided for the customer, who then needs only to sign a receipt to complete the transaction.
It is known in the art to encode data on a check with Magnetic Ink Character Recognition ("MICR") technology. In MICR technology, ferromagnetic indicia, or "magnetic ink" is used to print the customer's account number, a number identifying the bank, and the check number on each check. In the typical embodiment, alphanumeric characters are printed on the front face of a check with magnetic ink. The ferromagnetic particles in the magnetic ink are capable of holding a magnetic charge. Accordingly, when the characters are brought into proximity to a magnet, the magnetic ink is magnetically charged. The magnetically charged characters are then readable by a MICR reader. MICR readers read this information, for example, during the check clearing process to insure the proper account is charged with the amount for which the check is drawn.
MICR readers consist of a magnetic read head, a magnet, a device to advance the check (or other document printed with magnetic ink) past the read head and the magnet, and a device for holding the check or other document in proper relation to the read head. The read head typically has a curved surface and contains an active area, which is a narrow gap along the surface of the read head. Various approaches have been taken to keep documents in proper contact with the read head, including rollers, flat guides and high friction pads.
For example, in U.S. Pat. No. 3,801,804, by Von Glahan, et al., a mechanism comprising a rotating circular read head and a serpentine belt held against an arc of a rotating drum is disclosed. The methodology implemented in this patent requires several bearings along with the belt itself which are all susceptible to failure. No provision is made for documents having different thicknesses or stiffnesses. Further, the document being read must contact the belt and the drum throughout the extent of the contact area therebetween. The belt is always in contact with the roller, even with document present. In U.S. Pat. No. 4,031,359, by Christou et al., A Straightline Mechanism for Reading Documents, is disclosed. In this apparatus, no provision is made for holding a document securely against the read head to improve the efficiency of the reader. Further, the pressure pad disclosed within this patent is in the form of a metallic spring that will only permit a document to be fed through the apparatus in one direction. In U.S. Pat. No. 5,442,427 by Kogan, a magnetic transducer pressure pad is disclosed. The pressure pad is a flexible belt made of elastomeric material. The belt is spring-loaded against a read head and the pressure pad must contact the read head for the system to work. In U.S. Pat. No. 5,309,302 by Vollmann, is disclosed. A pressure pad is contained within a removable cassette. A read head is provided external to the cassette. The contact with a read head is aided by a spring-loaded felt pad with metal guides to advance and bias the pressure pad against the read head in a direction perpendicular to the path of travel of the tape. Further, no attempt has been made in this patent to conform the shape of the pressure pad to the read head.
Current point of sale check printers contain MICR readers for reading MICR encoding on the check and transmitting the encoded data to credit verification agencies. After the information regarding the customer's bank and account number is transmitted to the credit verification agency, a decision may then be made by the retailer whether to accept the presented check. The verification step is not necessary, as some point of sale check printers merely read and record the MICR-encoded data. After the MICR is read and any verification or approval completed, the back of the check is endorsed or franked.
Although the physical locations for endorsement and printing purchase information on checks have become somewhat standardized in recent years, other physical characteristics of checks such as their thickness and stiffness continue to vary widely from one customer's check to the next. Checks having differing widths may have MICR-encoded data in different relative positons. Checks to be read by a MICR reader may have creases or wrinkles from having been folded. Further, differing atmospheric conditions such as humidity levels may cause paper checks to respond differently inside a point of sale check printer. Finally, the printing in magnetic ink on a check may vary widely, such that one check may have a substantial quantity of magnetic ink and the next may have a lesser or even insufficient quantity of ink, making reading of the magnetic ink information difficult unless the check is held in close proximity to the read head.
What is needed is a means for reliable reading of MICR characters on checks and other documents having a variety of physical characteristics and under a variety of physical conditions.